Media stocker and paper feeder

ABSTRACT

A media stocker includes a feeder plate configured to maintain a plurality of recording media in a stacked state thereon, a vertically elevating device configured to cantilever-support the feeder plate, and a guide member disposed vertically to face a free end of the feeder plate and configured to guide the recording media stacked on the feeder plate. And the media stocker includes a roller attached to the free end side of the feeder plate and rotatable around a horizontal shaft, the outer circumferential surface of the roller being in contact with the guide member at a position higher than the position of the uppermost support point of the feeder plate by the elevating device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2009-213833, filed on Sep. 15, 2009, the entire content of which is incorporated herein by reference.

FIELD

Embodiments described herein relates generally to a media stocker for stacking and holding a recording medium to be fed into a paper feed opening of an image forming apparatus, the media stocker provided integrally with or separately from the image forming apparatus, a paper feeder using the media stocker, and a method for controlling the configuration of a recording medium stacked and held in the media stocker or the paper feeder.

BACKGROUND

A media stocker vertically elevates a feeder plate to allow a large number of recording media to abut against a pickup roller. In this construction, the media stocker may stock a number of recording media, for example, several hundred pieces.

As such, since the media stocker stocks a large number of recording media, a large force is applied to the feeder plate. For this reason, an elevating device for vertically elevating a feeder plate generally supports the feeder plate by holding both sides of the feeder plate, which are the upstream side and the downstream side in the direction of conveying a recording medium.

However, when a feeder plate is supported by holding both sides of the feeder plate, i.e., the upstream side and the downstream side in the direction of conveying a recording medium, a whole device becomes large-scaled and complicated in structure. Accordingly, in one embodiment, a media stocker has a feeder plate supported by holding one side of the feeder plate, i.e., a cantilever-supported feeder plate, as shown in FIG. 4.

In FIG. 4, A denotes a feeder plate which may elevate, and M denotes recording media. Elevating device E elevates feeder plate A to press recording media M against pickup roller PU. Pickup roller PU picks up to convey the uppermost of recording media M. At this point, separating device S separates only the uppermost of recording media M from the lower recording media.

As the number of recording media M stacked and held on feeder plate A increases, the weight of recording media M increases. Thus, in the construction of the media stocker, a free end of feeder plate A is inclined downwardly, as shown in FIG. 4. Consequently, the uppermost of recording media M stacked and held on the feeder plate is inclined to have a high position at the downstream side in the conveying direction.

However, in the related field to the media stocker, it is generally known that the desired configuration of the uppermost recording medium at the pickup position of a pickup roller is to remain level. If the uppermost of recording media M is inclined, the direction of picking up recording media M at pickup roller PU is also inclined, as shown in FIG. 4. Therefore, separation trouble may occur at separating device S, so as to cause a conveying failure. For example, the separation trouble at separating device S may cause a situation where the uppermost portion of recording media M cannot be properly separated, or skewing may occur in the structure of separating device S.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a front view.

FIG. 2 illustrates a perspective view showing a feeder plate and an elevating device viewed from an image forming apparatus side.

FIG. 3 illustrates a front view showing a feeder plate and an elevating device.

FIG. 4 illustrates a front view showing an example of a paper feeder in the related art.

DETAILED DESCRIPTION

According to an embodiment, a media stocker includes a feeder plate configured to maintain a plurality of recording media in a stacked state thereon, a vertically elevating device configured to cantilever-support the feeder plate, and a guide member disposed vertically to face a free end of the feeder plate and configured to guide the recording media stacked on the feeder plate. And the media stocker includes a roller attached to the free end side of the feeder plate and rotatable around a horizontal shaft, the outer circumferential surface of the roller being in contact with the guide member at a position higher than the position of the uppermost support point of the feeder plate by the elevating device.

Now, an exemplary embodiment will be hereinafter described in detail with reference to FIGS. 1 to 3. FIG. 1 is an entire front view. In one embodiment, paper feeder 31 includes media stocker 101 combined with pickup roller 41 and a separating device 51. Paper feeder 31, for example, stocks recording media M in media stocker 101. Pickup roller 41 picks up to convey the uppermost of recording media M in the media stocker. Separating device 51 separates the uppermost of recording media M from other recording media to feed the uppermost to a paper feed opening of an image forming apparatus (not shown).

Separating device 51 includes conveying roller 52 and separating roller 53 with feeding path SP of recording media M interposed therebetween. Conveying roller 52 is installed above feeding path SP and separating roller 53 is installed below feeding path SP. When pickup roller 41 begins to rotate for picking up to convey the uppermost of recording media M, conveying roller 52 rotates to apply conveying force to the picked one of recording media M. Separating roller 53 rotates together when conveying roller 52 begins to rotate. When the picked one of recording media M reaches a position just ahead of separating device 51, separating roller 53 pauses to rotate. However, at this point, as well as the uppermost of recording media M, other recording media of recording media M that are positioned below the uppermost are frictionally conveyed to separating device 51 by the pick-up and conveyance of pickup roller 41. In this respect, separating roller 53 pauses to rotate just before the picked one of recording media M reaches separating device 51, thereby other recording media positioned below the uppermost hit against separating roller 53 may be blocked. Then, only the uppermost of recording media M is separated from other recording media, and is conveyed to conveying roller 52 so as to be fed into a paper feed opening (not shown) of an image forming apparatus. In this case, a conveying force applied to the uppermost of recording media M by the rotation of conveying roller 52 is larger than a frictional force between the uppermost of recording media M and the blocked other recording media positioned just below the uppermost. Consequently, a plurality of recording media M picked up by pickup roller 41 are processed by separating device 51 so that only the uppermost of recording media M is separated to be fed.

In this respect, the pause of the rotation of separating roller 53 is performed by a one-way clutch (not shown). In addition, for example, whether the picked one of recording media M reaches a position just ahead of separating device 51 is determined by using a sensor 61 disposed between pickup roller 41 and separating device 51. In one embodiment, the sensor 61 may be a transmission type sensor, but not limited.

Moreover, separating device 51 is not limited the type as described above. For example, separating device 51 may be a reverse roller type.

Next, media stocker 101 is described. Media stocker 101 has feeder plate 103 attached to a sheet of base template 102 with feeder plate 103 being capable of elevating. Feeder plate 103 is cantilever-supported by base template 102 and is capable of elevating. Feeder plate 103 has a free end FE at a side opposite to the cantilever-supported side. Elevating device 104 elevates feeder plate 103. Thus, feeder plate 103 will be described after elevating device 104 is described.

FIG. 2 is a perspective view of feeder plate 103 and elevating device 104 viewed from an image forming apparatus aside. FIG. 3 is a front view of feeder plate 103 and elevating device 104 according to an exemplary embodiment. Elevating device 104 includes a pair of opposing elevating rollers 105 attached to a lower portion of feeder plate 103 to share a common horizontal line with rotatable around its horizontal shaft, and a pair of opposing rear-surface elevating rollers 106 opposite to feeder plate 103 with base template 102 interposed therebetween. The pair of opposing rear-surface elevating rollers 106 is mounted to single roller holding member 107 to share a common horizontal line with rotatable around its horizontal turning shaft. Also, base template 102 has three connecting holes 108 vertically extended with an elongated slot shape so that feeder plate 103 and roller holding member 107 are connected with each other through connecting holes 108. Thus, feeder plate 103 may elevate along base template 102 while being supported by opposing elevating roller pair 105 disposed on the front surface of base template 102 and opposing rear-surface elevating roller pair 106 disposed on the rear surface of base template 102. From the perspective of a support point where feeder plate 103 is supported, a portion where elevating roller pair 105 abut against base template 102 is support point LP positioned at the lowermost position, and a portion where rear-surface elevating roller pair 106 abut against base template 102 is support point UP positioned at the uppermost position (see FIG. 3).

In addition, elevating device 104 includes a pair of belt winding devices 109 disposed at both sides of base template 102. Each of belt winding devices 109 has endless belt 111 stretched between a pair of upper and lower pulleys 110. The lower pulley receives rotary force from a driving source (not shown) to rotate, which causes endless belt 111 to turn. In this respect, elevating device 104 has connecting section 112 provided on roller holding member 107 with connected to each of endless belts 111. Thereby, rotary force of endless belts 111 is transmitted to roller holding member 107 to elevate feeder plate 103.

As shown in FIGS. 1 to 3, media stocker 101 includes guide member 113 disposed vertically to face a free end of the feeder plate. Guide member 113 guides recording media M stacked on the feeder plate. Guide member 113 is attached to pivoting support member 116, and is pivotable about its horizontal shaft. Pivoting support member 116 is fixed to stud 115 mounted uprightly on bottom frame 114 of media stocker 101. Since guide member 113 is pivotable around its horizontal shaft, it may be opened to expose a space for receiving and dispensing recording media M with respect to feeder plate 103. An upper end of guide member 113 is detachable to a frame (not shown) of media stocker 101.

Bottom frame 114 of media stocker 101 also supports base template 102 to secure rigidity together with other frames of media stocker 101. Accordingly, bottom frame 114 and guide member 113 fixed at the upper end implement a strong and firm structure with rigidity.

Feeder plate 103 will now be described hereinafter. Feeder plate 103 includes roller 117 attached to free end FE. Roller 117 is rotatable around roller shaft 118, which is arranged horizontally, so as to be in contact with guide member 113. As shown in FIG. 3, roller 117 is in contact with guide member 113 at a position higher than the position where opposing rear-surface elevating roller pair 106 abut against base template 102. As described above, from perspective of a support point where feeder plate 103 is supported, a portion where rear-surface elevating roller pair 106 abut against base template 102 is support point UP positioned at the uppermost position. Thus, contact position CP where roller 117 attached to free end FE of feeder plate 103 abuts against guide member 113 is positioned higher than the position of the uppermost support point UP of feeder plate 103 by elevating device 104.

The outer circumferential surface of roller 117 is disposed to be in contact with guide member 113. In this respect, the contact between roller 117 and guide member 113 may be a constant contact or temporary contact which occurs when a stack of recording media M are loaded on feeder plate 103. In other words, roller 117 may be slightly separated from guide member 113 when recording media M are not loaded on feeder plate 103, and may be in contact with guide member 113 when recording media M are loaded on feeder plate 103 to make feeder plate 103 inclined downwardly due to its weight. In this case, roller 117 may be in contact with guide member 113 when at least a predetermined maximum number of recording media M should be loaded on feeder plate 103.

From the foregoing, as shown in FIG. 3, a triangle is formed by the uppermost support point UP of feeder plate 103 where rear-surface elevating roller pair 106 abut against base template 102, the lowermost support point LP of feeder plate 103 where elevating roller pair 105 abut against base template 102, and contact position CP where roller 117 abuts against guide member 113. In this case, the triangle is an obtuse angled triangle in which an angle formed by a side between support point LP and support point UP and a side between support point UP and contact position CP is an obtuse angle.

Under such a construction, media stocker 101 stocks and stores a large number of recording media M so as to prepare for the pickup and conveyance of recording media M by pickup roller 41. Recording media M are placed on feeder plate 103 for stock. As such, a plurality of recording media M are stacked and stored by feeder plate 103, which may elevate recording media M.

Subsequently, as the number of the stacked recording media M increases, free end FE of feeder plate 103 may be inclined downwardly due to the weight of recording media M. At this point, a turning trajectory according to the downwardly inclining movement of free end FE is convex outwardly from a vertical plane including free end FE at its initial position. This is because the triangle formed by support point UP, support point LP and contact position CP has an obtuse angle formed by a side between support point LP and support point UP and a side between support point UP and contact position CP. Accordingly, roller 117 abuts against guide member 113 so that free end FE of feeder plate 103 can be prevented from being inclined downwardly.

In this respect, when free end FE of feeder plate 103 starts to be inclined downwardly due to the weight of the plurality of recording media M stacked and held on the feeder plate, guide member 113 supports the position where a turning trajectory according to the downwardly inclining movement of free end FE is convex outwardly from a vertical plane including free end FE at its initial position.

As described above, according to the exemplary embodiment, since the downwardly inclining movement of feeder plate 103 is prevented by guide member 113, although feeder plate 103 is cantilevered, the configuration of the uppermost of recording media M stacked on feeder plate 103 can be maintained level. As a result of maintaining level the configuration of the uppermost of recording media M, pickup roller 41 pick up and convey recording media M with maintaining level, so that separating device 51 may separate and feed without causing problems. Accordingly, a failure in conveying recording media M can be prevented.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel media stocker, paper feeder using the media stocker, and method for controlling the configuration of a recording medium described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the media stocker, the paper feeder using the media stocker, and the method for controlling the configuration of a recording medium described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions. 

What is claimed is:
 1. A media stocker comprising: a feeder plate configured to maintain a plurality of recording media in a stacked state thereon; a vertically elevating device configured to cantilever-support the feeder plate; a guide member disposed vertically to face a free end of the feeder plate and configured to guide the recording media stacked on the feeder plate; and a roller attached to the free end of the feeder plate and rotatable around a horizontal shaft, the outer circumferential surface of the roller being in contact with the guide member at a position higher than the position of the uppermost support point of the feeder plate by the elevating device.
 2. The stocker of claim 1, wherein the roller is placed into contact with the guide member when at least a predetermined maximum number of recording media are loaded on the feeder plate.
 3. The stocker of claim 1, wherein a lower end of the guide member is pivotable around its horizontal shaft, and an upper end of the guide member is detachable therefrom.
 4. The stocker of claim 1, further comprising a separating device disposed opposite the free end side of the feeder plate, the separating device being configured to separate only the uppermost recording media.
 5. The stocker of claim 4, further comprising a sensor configured to detect whether the recording media reaches a position just ahead of the separating device.
 6. The stocker of claim 1, wherein the roller is separated from the guide member when the recording media are not loaded on feeder plate, and the roller is placed into contact with the guide member when the recording media are loaded on feeder plate so as to cause the feeder plate to incline downward.
 7. The stocker of claim 1, wherein the feeder plate is held by one side.
 8. A paper feeder comprising: a feeder plate configured to maintain a plurality of recording media in a stacked state thereon; a vertically elevating device configured to cantilever-support the feeder plate; a guide member disposed vertically to face a free end of the feeder plate and configured to guide the recording media stacked on the feeder plate; a roller attached to the free end side of the feeder plate and rotatable around a horizontal shaft, the outer circumferential surface of the roller being in contact with the guide member at a position higher than the position of the uppermost support point of the feeder plate by the elevating device; and a pickup roller configured to pick up and convey the uppermost of recording media stacked on the feeder plate to a paper feed opening of an image forming apparatus.
 9. The feeder of claim 8, further comprising a separating device disposed opposite the free end side of the feeder plate, the separating device being configured to separate only the uppermost from the recording media picked-up and to convey the uppermost of recording media to the pickup roller.
 10. The feeder of claim 9, further comprising a sensor disposed between the pickup roller and the separating device, the sensor being configured to detect whether the recording media reaches a position just ahead of the separating device.
 11. A mass media stocker for stacking and holding a plurality of recording media on a cantilever-supported feeder plate and for feeding the uppermost of the recording media to a paper feed opening of an image forming apparatus, the feeder plate capable of elevating the recording media, the stocker media stocker comprising: a guide member disposed vertically to face the free end of the feeder plate so as to guide the recording media stacked on the feeder plate, wherein when the free end of the feeder plate is inclined downward due to the weight of the plurality of recording media stacked and held thereon, the guide member supports the position where a trajectory according to the downwardly inclining movement of the free end is convex outwardly from a vertical plane including the free end at its initial position.
 12. The stocker of claim 11, further comprising a separating device configured to separate only the uppermost recording media.
 13. The stocker of claim 12, further comprising a sensor configured to detect whether the recording media arrived the position just before the separating device.
 14. A feeder comprising: a media stocker configured to stack and hold a plurality of recording media on a cantilever-supported feeder plate and further being configured to feed the uppermost of the recording media to a paper feed opening defined by an image forming apparatus, the feeder plate being capable of elevating the recording media, the media stocker comprising a guide member disposed vertically to face the free end of the feeder plate so as to guide the recording media stacked on the feeder plate, wherein when the free end of the feeder plate is inclined downward due to the weight of the plurality of recording media stacked and held thereon, the guide member supports the position where a trajectory according to the downwardly inclining movement of the free end is convex outwardly from a vertical plane including the free end at its initial position; and a pickup roller configured to pick up to convey the uppermost of recording media stacked on the feeder plate to the paper feed opening of defined by the image forming apparatus.
 15. The feeder of claim 14, further comprising a separating device disposed opposite the free end side of the feeder plate, the separating device being configured to separate only the uppermost from the recording media picked-up and to convey the uppermost of recording media to the pickup roller.
 16. The feeder of claim 15, further comprising a sensor disposed between the pickup roller and the separating device, the sensor being configured to detect whether the recording media reaches a position just ahead of the separating device.
 17. A method for controlling the configuration of recording media, the method comprising: stacking and holding a plurality of recording media on a cantilever-supported feeder plate, the feeder plate capable of elevating the recording media; and supporting the position of the feeder plate so as to prevent a trajectory according to the downwardly inclining movement of the free end of the feeder plate from being convex outwardly from a vertical plane including the free end at its initial position, when the free end is inclined downwardly due to the weight of the plurality of recording media stacked and held on the feeder plate.
 18. The method of claim 17, further comprising picking up the recording media to convey the recording media stacked on the feeder plate.
 19. The method claim 17, further comprising separating only the uppermost recording media picked-up and conveyed to the pickup roller.
 20. The method of claim 19, further comprising sensing to detect whether the recording media reaches a position just before separating. 